Rotating drill chuck for percussive tools



June 4, 1929. G. T. CHAPMAN ROTATING DRILL CHUCK FOR PERCUSSIVE TOOLS Filed Nov. 17, 1924 IN V EN TOR @07 6 7 BY j flmzwzs Patented June 4, 1929.

GEORGE '1'. CHAPMAN, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR 1,716,114 PATENT osmosis,

a I J r re em l.

:snnc'rnrc 'rooI. COMPANY, a CORPORATION 01'' rnimsnvaxm. nom'rmenm enucx ron rnncusslvn 'rooLs;

Application filed November 17, 1824. Serial No. 750,236.

My invention relates to rotating chucks for use with percussive tools.

The object of my invention is to provlde a rotating chuck that will rotate a drlh 5 operated by a percussive tool to drlll holes in stone, concrete, etc.

Another object of my invention is to obviate the necessity of a rotating wrench which has been heretofore used to rotate the drill while a hole was being drilled thereby. In drilling holes in stone, concrete or similar materials, the drill of the usual type employed for this purpose must be rotated while being struck. The necessity for rotating a drill while striking it is that in 1ts action it operates as a rotating chlsel, chipping ofl:', bit by bit, the stone or other material upon which the cuttmg surfaces 1mpinge, in such manner as to cut or chip a hole in the material. When actuated by percussive tools of the .electric hammer type, it has been customary to rotate the drill by means of a rotating wrench. The operator held the hammer in one hand and the rotating wrench in the other, thus giving him a two point support for the hammer. It was necessary, however, to rotate the wrench which constituted one of such two points. While this was 30 not an extreme disadvantage when drilling holes downward, as in a floor, it was somewhat of a disadvantage when drillin holes horizontally into a wall, or vertical y'into a ceiling. Even when drilling into a floor, there was some disadvantage due to the fact that it was necessary to move the rotating wrench continuously through an angle of substantially ninety degrees where a drill with four flutes was employed. If the drill was not turned fast enough there was liability of the drill jamming and necessitating the stopping and re-starting of the hammer, with a consequent delay 1n drilling.

By means of a rotating chuck of the character which I provide, the drill is automatically rotated while it is struck b the hammer, and the operator is enable to devote his entire attention to supporting the hammer at the proper p'osition.

The chuck which I provide comprises a striking element or anvil which is subjected to the striking force of he hammer or percussive tool. A housin enclosing the striking surface of the anvil supports a bearing through which a tool socket extends into the housing, exposing an impact receiving surface to the striking surface of the anvil. A circular aw is disposed on a flange of the socket and surrounds the anvil within the housing. The circular ed e or rim of 60 the jaw is provided with teet which two pawls supported on the inside of the housmg engage. When the anvil is caused to strike the toolsocket, the pawl actuates the tool socket, by means ofthe teeth, to rotate the socket and the drill while the force of the blow acts upon the drill to cause it to do work. In order to prevent the weight of the hammer or percussive tool from pressing the anvil down against the tool socket, and also to enable the pawls to assume new act1ve positions to engage subsequent teeth, a helical spring is disposed to normally separate the anvil and the impact receiving surface of the tool socket.

Fig. 1 of the accompanying drawings is an elevational view illustrating the arrangement of a rotating chuck in a percussive machine of the electric hammer type;

Fig. 2 is a longitudinal view, partially 1n section and partially in elevation of the chuck embodying my invention;

Fig. 3 is a vertical sectional view of the housing on the "chuck; 1

Fig. 4 is a bottom view of the housing illustrated in Fig. 3; and

Figs. 5 and 6 are respectively plan and side elevational views of the pawls employed in the chuck.

In Fig; '11 is merely illustrated a percus- 9o sive mac ine orthe electric hammer 1 which acts upon the drill 2 through -a chuck 3 to rotate the drill while causing it to drill holes in the material being worked upon.

The chuck 3 is illustrated in a specific 05 form by Fig. 2 and comprises, in general, an anvil 5, a housing 6, a bearing 7, a tool socket 8., a spring 9 and a pawl 10 for engaging teeth 11 on a circular jawconstituting part, of the socket 8.

The anvil 5 comprises a shank 15 of hexagonal shape for receiving an impact force from the hammer, a striking surface 16 for transmitting the impact force and a threaded portion 17 backed by a shoulder 18 to permit the anvil to be securely threaded into the housing 6.

Thehousing 6 is of circular cup-shape having the anvil 5 threaded into the base thereof. The base is provided with a raised innerfpor-tion 19 which serves as a guide for the pawl and acts as a seat for the spring 9. In the opening of the housing 6 is threaded a supporting flange 20 for the bearing 7 which is then tightly secured to the housing by means of a machine screw 21 and lock washer 22.

The tool socket8 comprises a guide 23 for the drill, having an opening therethrough,

the upper portion of which is of hexagonal shape to preclude relative movement between the drill and the socket. A flange 24 on the end of the guide 23 of the socket con teeth 11 which are adapted to be engaged by the pawl 10.

The pawl 10 is pivoted on a p1n'26 sup ported in the seat 19 of the housing. spring 27 seated inthe housing engages a tip 28 on the heel of the pawl and serves to maintain the pawl in engagement with the toothed surface of the circular jaw of the tool socket. f j

Only one pawl is illustrated in the figure but in the present chuck I employ two pawls each of which is alternately operative to en.- gage a tooth and rotate the tool socket. Where it is desirable to provide larger teeth in the jaws in order to obtain greater strength, the number of pawls may be increased. For example, ifrhalf the number of teeth are employed the same speedof rotation will be obtained by doubling the number of pawls. The manner in which the pawls are secured in position will 'be understood upon considering Figs. 3 and lwhich illustrate the construction of the housing. Holes 30 and 31 are drilled through the side of the housing into'the seat 19. Each pawl issthen placed in proper position to receive apin or shaft- 26 which may then be suitably secured in position-to prevent it from failing out during operation of the hammer upon the chuck.

Openings 32 and 33 are provided in the housing directly above the shafts 26 and are adapted to receive oil fcups or valves through which the shafts 26 may be oiled to permit free movement of the 'pawls.

Two small recesses 34 and 35 areprovided in the seat 19 of the housing and are adapted-to retain in position one end of the j springs 27 which pawls.

The

rests" against the .heels of When the operator starts the hammer 1,

awls are formed "from cylinders-ofapprox mately the same diameter as the cir- 1 by closing the trigger switch 40 the handle,a striking element, whichin this case is "a core reciprocating between two solenoids (not shown), strikesitheen'd of the shank 156i the'chuck. The kinetic energy of the striking element is imparted to the handle 5 Wlll('ll moves downward against the coinpresslon force of the s ring 9 and strikes .the" force-receiving sur ace 36 of the tool socket 8. The force of this blow is transmitted-to the drill 2 by the inside shoulders 37 of the tool socket. The shank of the drill should be hexagonal in shape to fit the henagonal opening 38 of the tool socket8. The end of the shank of the drill should 'not extend above the impact receiving surface 36.

As the anvil 5 has moved downwardly under the force of the blow, the housing 6 has acted upon the pawl 10 to cause it to push against one of the teeth not the tool socket to thereby turn the socket through a corresponding angle. With each recurring A blow, the socket is turned a distance correspending to half the tooth pitch. After the working energy of each blow is transmitted to the tool or drill, the spring 9, by reason of its compressed condition and the backlash of the hammer, raises the anvil and the housing to its initial position at which it is ready to receive the next blow from the striking element of the hammer. When the anvil isrestored to its initial position, one

rotate the tool socket through a. relatively I small angle. With each recurringblow the .drill is struck to do useful work and at the same time is rotated so that it will not strike the same place twice in succession.

By employing a rotating chuck of this character to rotate the drill while drilling holes in stone or concrete, the operator is permitted to devote his entire attention to holding and supporting the hammer at the proper position at which he desires to work. By means of the present chuck a working blow from the ercussive machine is transformed into a irect working stroke and a turning torque on the drill. 1

While I have shown a preferred form of structure embodying my"'invention, structural modifications may be made therein without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim as my invention:

holder adapted to hold a working tool inthe path of movement of the impact element, means responsive to a forward'movement 1. A rotating chuck for a percussive machine comprising an impact element, a tool t1ve movement to the tool hol a normally maintainin the chuck an er, and means for normally maintaining a spaced relation between the impact element and the tool holder.

2. A rotating chuck for a percussive maine comprising an impact element, a tool holder adapted to hold a working tool in the path of rmovement of the impact element, means controlled by movement of the impact element for rotating the tool holder, and a spring disposed between the impact element and the tool holder of sufficient strength to su port a percussive machine on to preclude the mere weight of the machine from forcing the impact element down upon the tool holder.

3. A rotating chuck for percussive tools comprising an impact element, an enclosing housing disposed thereon, rection of impact, a bearing threaded into the 0 en end of the housing, a. tool socket extending through the bearing into the housing, a spring for normally maintainin a spaced relation between the housing and the tool socket,.and means responsive toa change in such spaced relation for turning the tool socket.

4. A rotating chuck for use with percussive machines, comprising an impact element provided with an impact receiving surface and an impact delivering surface, a cup threaded onto said element behind the impact delivering surface and facing in the' direction of im act, a bearing disposed at the open end 0% the cup, a tool socket extending through the bearing into the cup and provided with an impact receiving surface and a toothed circu ar end surface, a, spring surrounding the impact element and w a spaced relation between the impact de ivering surface of the impact element and the impact receiving surface of'the tool socket, and a pawl disposed on the inside of the cup to engage the toothed end surface of the tool socket and arranged to turn the socket each time the-impact element strikes the socket.

5. A rotating chuck for use with percussive tools comprising an anvil, a housin therefor, a bearing in the forward end 0 the housing, a tool socket extending throu h the bearing and spaced from the anvil stri ing surface, a spring for normall maintaining such spaced relationship, an means cooperating with the housing and the tool socket for rotating the socket as the anvil strikes the socket.

6. A drill chuck for use with percussive tools, comprising a drill holder, an element for receiving the impact of the percussive tool, means for translating a portion of the energy of impact to produce a turning torque on the drill holder, and means for returning of the impact element for imgarting a rotasaid imp facing in the di-' act element to normal position between impacts of the percussive tool.

7. A chuck for effecting intermittent rotative movements of a tool comprising an impact element terminating in a member adapted to be detachably associated with a percussive machine in the path of its reciprocatory member, a tool holder rotatably mounted on said impact element, said tool holder having a surface for receiving direct impact of said element, and means responsive to impact upon said impact element for rotating said tool holder.

8. A chuck for effecting intermittent rotative movements of a tool comprising an impact element terminating in a member adapted to be detachably associated with a percussive machine in the path of its reciprocatory member, a tool holder carried by said impact element and movable longitudinally, and rotatably with respect thereto, said tool holder having a surface for receiving direct impact of said element, and means responsive to imp ment for rotating said tool holder.

9. A chuck for effecting intermittent rotative movements of a tool comprising an impact element terminating in a shank adapted to be detachably associated with a percussive machine in the path of its reciprocatory member, a tool holder carried by said impact element and movable longitudinally and rotatably with respect thereto, a spring interposed between said impact element and tool holder, and. means responsive to impact upon said impact element for rotating said tool holder.

10. A chuck for effecting intermittent rotative movements of a tool comprising an impact element terminating in a shank adapted to be associated with a percussive machine in the path of its reciprocatory member, a tool holder carried b pact element and movable longitu inally and rotatably with respect thereto, a spring interposed between said impact element and tool holder, and means comprising pawl and ratchet mechanism responsive to impact upon said impact element for rotating said tool holder.

11. A chuck for effecting intermittent rotative movements of a tool comprising an impact element having a skirt and terminating in a shank adapted to be detachably associated with a percussive machine in the path of its reciprocatory member, a tool holder comprising a sleeve mounted within said skirt and movable longitudinally and rotatably with respect thereto, a spring confined within said skirt between said impact element and tool holder, and means responsive to impact upon said impact element for rotating said tool holder. 7

12. The combination with a percussive said im-' act upon said impact elemachine and'its reciprocatory core member, of a chuck foreflecting intermittent rotative movements of a tool comprising an impact element reciprocated by said core member, a tool holder carried by said impact element and movable longitudinally and rotatably with respect thereto, said tool holder having a surface for receiving direct impact of said element, and co-acting pawl and ratchet mechanism for imparting intermittent r0- tative movement of said tool holder.

13. The combination with a percussive machine and its reciprocatory core member, of a chuck for effecting intermittent rotative movements of a tool comprising an impact element reciprocated by said core memher and having, a skirt, a tool holder mounted in said skirt and movable longitudinally 14. A chuck for use 1n combination with a percussive device, comprising a tool holder, an impact element for directly striking said tool holder and transmitting concnssive force thereto, and means other than said impact-transmitting means, for engaging said tool holder and imparting relative motion thereto during the force transmitting stroke of said impact element.

In testimony whereof, I have hereunto subscribed my name this 5th day of November, 1924.

GEORGE T. CHAPMAN. 

